( 1) 66x+ 17y=3967
25x+y= 1200
Answer: x=48 y=47.
(2) 18x+23y=2303
74x-y= 1998
Answer: x=27 y=79
(3) 44x+90y=7796
44x+y=3476
Answer: x=79 y=48
⑷76x-66y = 4082
30x-y=2940
Answer: x=98 y=5 1.
(5) 67x+54y=8546
7 1x-y=5680
Answer: x=80 y=59
(6) 42x-95y=- 14 10
2 1x-y= 1575
Answer: x=75 y=48
(7) 47x-40y=853
34x-y=2006
Answer: x=59 y=48
(8) 19x-32y=- 1786
75x+y=4950
Answer: x=66 y=95
(9) 97x+24y=7202
58x-y=2900
Answer: x=50 y=98
( 10) 42x+85y=6362
63x-y= 1638
Answer: x=26 y=62
( 1 1)85x-92y =-25 18
27x-y=486
Answer: x= 18 y=44.
( 12) 79x+40y=24 19
56x-y= 1 176
Answer: x=2 1 y= 19.
( 13) 80x-87y=2 156
22x-y=880
Answer: x=40 y= 12.
( 14) 32x+62y=5 134
57x+y=2850
Answer: x=50 y=57
( 15) 83x-49y=82
59x+y=2 183
Answer: x=37 y=6 1.
( 16) 9 1x+70y=5845
95x-y=4275
Answer: x=45 y=25.
( 17) 29x+44y=528 1
88x-y=3608
Answer: x=4 1 y=93.
( 18) 25x-95y=-4355
40x-y=2000
Answer: x=50 y=59
( 19) 54x+68y=3284
78x+y= 1404
Answer: x= 18 y=34.
(20) 70x+ 13y=3520
52x+y=2 132
Answer: x=4 1 y=50.
(2 1) 48x-54y=-3 186
24x+y= 1080
Answer: x=45 y=99
(22) 36x+77y=76 19
47x-y=799
Answer: x= 17 y=9 1.
(23) 13x-42y=-27 17
3 1x-y= 1333
Answer: x=43 y=78
(24) 28x+28y=3332
52x-y=4628
Answer: x=89 y=30
(25) 62x-98y=-2564
46x-y=2024
Answer: x=44 y=54.
(26) 79x-76y=-4388
26x-y=832
Answer: x=32 y=9 1.
(27) 63x-40y=-82 1
42x-y=546
Answer: x= 13 y=4 1.
(28) 69x-96y=- 1209
42x+y=3822
Answer: x=9 1 y=78.
(29) 85x+67y=7338
1 1x+y=308
Answer: x=28 y=74
(30) 78x+74y= 12928
14x+y= 12 18
Answer: x=87 y=83.
(3 1) 39x+42y=533 1
59x-y=584 1
Answer: x=99 y=35
(32)29x+ 18y = 19 16
58x+y=2320
Answer: x=40 y=42
(33) 40x+3 1y=6043
45x-y=3555
Answer: x=79 y=93
(34) 47x+50y=8598
45x+y=3780
Answer: x=84 y=93
(35) 45x-30y=- 1455
29x-y=725
Answer: x=25 y=86
(36) 1 1x-43y =- 136 1
47x+y=799
Answer: x= 17 y=36.
(37) 33x+59y=3254
94x+y= 1034
Answer: x= 1 1 y=49.
(38) 89x-74y=-2735
68x+y= 1020
Answer: x= 15 y=55.
(39) 94x+7 1y=75 17
78x+y=3822
Answer: x=49 y=4 1.
(40) 28x-62y=-4934
46x+y=552
Answer: x= 12 y=85.
(4 1) 75x+43y=8472
17x-y= 1394
Answer: x=82 y=54
4 1x-38y =- 1 180
29x+y= 1450
Answer: x=50 y=85
(43) 22x-59y=824
63x+y=4725
Answer: x=75 y= 14.
(44) 95x-56y=-40 1
90x+y= 1530
Answer: x= 17 y=36.
(45) 93x-52y=-852
29x+y=464
Answer: x= 16 y=45.
(46) 93x+ 12y=8823
54x+y=49 14
Answer: x=9 1 y=30.
(47) 2 1x-63y=84
20x+y= 1880
Answer: x=94 y=30
(48) 48x+93y=9756
38x-y=950
Answer: x=25 y=92
(49) 99x-67y=40 1 1
75x-y=5475
Answer: x=73 y=48
(50) 83x+64y=929 1
90x-y = 3690 1。 Party A and Party B each have several books. If Party A gives Party B 10, then the number of people is equal. If Party B gives Party A 10, then the number of books of Party A is twice that of Party B. Ask how many books each has.
Solution: a x b y
x- 10=y+ 10
2(y- 10)=x+ 10
x=70，y=50
2. The distance between Party A and Party B is 265,438+0 km. If they go in the opposite direction, they will meet 1 hour. If they go in the same direction, Party B will catch up with Party A within 7 hours. Ask Party A and Party B for speed.
Solution: a xkm/h, b y
(x+y)=2 1
7(y-x)=2 1
x=9，y= 12
3. A rectangle, if its length is reduced by 3cm and its width is increased by 2cm, becomes a square. The two figures have the same area, and the sphere is long and wide.
Solution: length x width y
x-3=y+2
xy=(x-3)(y+2)
x=9，y=4
4.4 The passenger capacity of five cars is 27t, and the passenger capacity of six cars 10 car is 51t.. Passenger cargo. How many tons can each cart and trolley carry?
Solution: big x and small y
4x+5y=27
6x+ 10y=5 1
x= 1.5，y=4.5
5. 150 people took the test, with an average score of 55, 77 for those who passed, and 47 for those who failed. How many people are in each group?
Solution: Fail Y through X.
x+y= 150
77x+47y=55* 150
x= 1 10，y=40
6. There are 90 people in the workshop, and each person can make 12 A parts or 15 B parts a day. How to arrange and match the parts (1a and 1b)?
Solution: x people do a and y people do B.
x+y=90
12x= 15y
x=50，y=40
7. Every 3 meters of cloth can be made into 2 coats or 3 pairs of pants. How many sets can 600 meters of cloth be made? (1 clothes 1 pants 1 set)
Solution: Let's make X-shirts and Y-pants.
x=y
3/2x+y=600
X = 240, Y = 240 can make 240 sets.
8. There are some instruments in Beijing and Shanghai that can be used in other places, including 4 in Beijing 10 and Shanghai. It is known that Chongqing needs 8 and Wuhan needs 6. The transportation expenses of instruments from Beijing and Shanghai to Chongqing and Wuhan are shown in the following table. The relevant departments plan to transport these instruments with 8000 yuan. Please design a plan to enable Wuhan and Chongqing to get the necessary instruments, and the freight is just enough.
Wuhan Chongqing
Beijing 400 800
Shanghai 300 500
Solution: Set Beijing to transport to Wuhan X Station and Shanghai to Wuhan Y Station.
x+y=6
400 x+800( 10 x)+300y+500(4y)= 8000
x=4，y=2
That is, Beijing transported 4 sets from Shanghai to Wuhan, 6 sets to Chongqing, 2 sets to Wuhan and 2 sets to Chongqing. As can be seen from the freight table, the unit freight rate from Beijing to Chongqing is the highest. Considering the reduction of freight, for example, the number of trains from Beijing to Chongqing is reduced to five. At this point, the total freight rate is
400× 5+800× 5+300+500× 3 = 7800, which is lower than the original 200 yuan. It can be adjusted appropriately to continue to reduce the total freight.
10. The school library moved. Students from Class 3, Grade 8 took part in the task of moving and arranging books. At the beginning, the number of people involved in carrying books was twice as small as that of four people sorting books. Later, four people were transferred from the students carrying books to take part in the book sorting work. At this time, the number of people in the two parts is equal. How many people need to endorse and read the whole book?
Let's assume that the number of people involved in carrying books and sorting books is X and Y respectively.
x-2y=-4
x-y=8
x=20，y= 12
Inequality group: 1. There is 6 cubic meters 18 of water in the container. Now, it is necessary to inject 8 cubic meters of water into the container so that the temperature of the mixed water in the container is not lower than 30 degrees and not higher than 36 degrees. What is the temperature range of the injected 8 cubic meters of water?
Let the temperature of injected water be x.
( 18 * 6+X * 8)/(6+8)& lt； 36
( 18*6+X*8)/(6+8)>30
There are several red and white balls. It is known that the number of white balls is less than that of red balls, but it is twice that of red balls. If each white ball counts as 2 and each red ball counts as 3, the total is 60. How many white balls and red balls are there?
There are x red balls and y white balls.
Y & ltX
2Y & gtX
3X+2Y=60
There are 25 multiple-choice questions in an exam. If you do a right question, you will get 4 points, if you do a wrong question, you will get 2 points, and if you don't get 0 points, if Xiao Ming wants to ensure that his test score is above 60 points, then what inequality should he satisfy if he does at least the right question X?
If it is set to question X, then 25-x question 4x -(25-x) =80 x=2 1 is it wrong or not?
There are 5 rooms less on the first floor of the hotel than on the second floor, and there are 48 people in a tour group. If all are arranged on the first floor, there are four people in each room, and the room is not enough, and there are five people in each room, and the room is not full; If you arrange to live on the second floor, each room is not enough for 3 people, and each room is 4 people. If some rooms are not full, ask how many rooms are on the first floor of the hotel.
Set up room X on the first floor and room Y on the second floor.
Then: 4x
9+3/5 & lt； X< 12 ... so x= 10 or 1 1.
3y & lt48，4y & gt； 48
12 & lt； Y< 16 ... so y= 13, 14, 15.
And x=y-5.
Therefore, x= 10. y= 15。
5. Give some books to some students. If you give each student three books, the remaining eight books. If each student in front gets five books, then the last student gets less than three. How many books are there? How many students are there?
There are x students.
3X+8≤[X- 1]×5+2 X≥5.5 means that * * * has 6 students, and the notebook is 3×6+8=26.
6. Several children in kindergarten were given a box of apples. If each child is divided into three parts, then the remaining seven parts; If everyone gets five apples, 1 person gets less than five apples. How many children are there? How many apples?
There are x children and (3X+7) apples.
5(x- 1)≤3x+7 & lt； 5x
Solution: 3.5≤X≤5.5
Then X=4 or X=5.
When X=4, 3X+7= 19;
When X=5, 3X+7 = 22；;
There are 4 children, 19 apples; Or have five children and 22 apples.
7. The monthly water fee for small houses shall not be less than 15 yuan. According to the regulations of the water supply company, if the monthly water consumption of each household does not exceed 5 cubic meters, it will be per cubic meter 18 yuan. The monthly water consumption of each household exceeds 5 cubic meters, exceeding the 2 yuan per cubic meter. What is the minimum water consumption for small houses?
Make it at least x cubic meters.
1.2× 5+2 (x-5) ≥156+2x-10 ≥15x ≥ 9.5 is at least 9.5 cubic meters.
8 Pump the pool water with the A-type pump that can pump 1. 1 ton of water per minute, and it will be finished in half an hour. If you use a B-type pump, it is estimated that it will be finished in 20 to 22 minutes. How many tons of water does type B pump pump per minute more than type A pump?
Let the B pump pump X tons more water per minute than the A pump.
20( 1. 1+x)& lt； 30* 1. 1 ⑴
22( 1. 1+x)>30* 1. 1 ⑵
From (1): x
from(2):x & gt； 0.4
∴ The solution set of inequality group is 0.55 >:x>；; 0.4
9. There are 530 seventh-grade students, including 1/9 boys and 20 girls who signed up for sports competitions. The rest of the students are equal in number. How many boys and girls are there in the seventh grade?
There are x boys and y girls.
Then x+y=530.
x-x/9=y-20
The solution is x=270.
y=260
10 several cars were used to transport a batch of goods, weighing 8 tons. If each car is loaded with 4 tons, there are 20 tons of goods left; If it is not lit, it will be fully loaded with 8 tons, and the last car will be dissatisfied and not empty. Q: How many cars are there?
If there are ***x cars in total, the total * * is 4x+20 tons.
8x & gt4x+20
X> v
4x+20 & gt； 8(x- 1)
X< seven
5 & ltx & lt7。 And x is an integer, so x=6.
1 1 Autumn outing for the second grade, if you rent more than 48-seat buses, it will just be full; If you rent a 64-seat bus, you can rent one less, and one bus is full, but more than half. You have been renting 48-seat and 64-seat buses for each 250 yuan and 300 yuan. What kind of bus is economical to rent?
Rent 64 buses x and rent 48 buses (X+ 1).
64X-48(X+ 1)>64÷2
64X-48(X+ 1)